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Voltage-gated Na+ channels (VGSC) are transmembrane proteins that are essential for the initiation and propagation of action potentials in neuronal excitability. Because neurons express a mixture of Na+ channel isoforms and protein kinase C (PKC) isozymes, the nature of which channel is being regulated by which PKC isozyme is not known. We showed that DRG(More)
Alpha1D L-type Ca channel was assumed to be of neuroendocrine origin only; however, alpha1D L-type Ca channel knockout mice exhibit sinus bradycardia and atrioventricular block, indicating a distinct role of alpha1D in the heart. The presence and distribution of alpha1D Ca channel in the heart and its regulation by protein kinase A (PKA) are just emerging.(More)
After myocardial infarction (MI), the noninfarcted myocardium undergoes significant hypertrophy as part of the post-MI structural remodeling. Electrophysiological changes associated with the hypertrophied remodeled myocardium may play a key role in arrhythmia generation in the post-MI heart. We investigated the cellular and ionic basis of arrhythmias in(More)
The recent discovery of zinc signals and their essential role in the redox signaling network implies that zinc homeostasis and the function of zinc-containing proteins are probably altered as a result of oxidative stress, suggesting new targets for pharmacological intervention. We hypothesized that the level of intracellular labile zinc is changed in hearts(More)
The novel alpha1D Ca2+ channel together with alpha1C Ca2+ channel contribute to the L-type Ca2+ current (I(Ca-L)) in the mouse supraventricular tissue. However, its functional role in the heart is just emerging. We used the alpha1D gene knockout (KO) mouse to investigate the electrophysiological features, the relative contribution of the alpha1D Ca2+(More)
Congenital heart block (CHB) is a conduction abnormality characterized by complete atrioventricular (AV) block. CHB affects fetuses and/or newborn of mothers with autoantibodies reactive with ribonucleoproteins 48-kDa SSB/La, 52-kDa SSA/Ro, and 60-kDa SSA/Ro. We recently established animal models of CHB and reported, for the first time, significant sinus(More)
The novel alpha(1D) L-type Ca(2+) channel is expressed in supraventricular tissue and has been implicated in the pacemaker activity of the heart and in atrial fibrillation. We recently demonstrated that PKA activation led to increased alpha(1D) Ca(2+) channel activity in tsA201 cells by phosphorylation of the channel protein. Here we sought to identify the(More)
The Ca(v)1.3 (alpha(1D)) variant of L-type Ca(2+) channels plays a vital role in the function of neuroendocrine and cardiovascular systems. In this article, we report on the molecular and functional basis of alpha(1D) Ca(2+) channel modulation by protein kinase C (PKC). Specifically, we show that the serine 81 (S81) phosphorylation site at the(More)
Voltage gated sodium channels (Nav) are transmembrane proteins responsible for action potential initiation. Mutations mainly located in the voltage sensor domain (VSD) of Nav1.5, the cardiac sodium channel, have been associated with the development of arrhythmias combined with dilated cardiomyopathy. Gating pore currents have been observed with three(More)
Three weeks after myocardial infarction (MI) in the rat, remodeled hypertrophy of noninfarcted myocardium is at its maximum and the heart is in a compensated stage with no evidence of heart failure. Our hemodynamic measurements at this stage showed a slight but insignificant decrease of +dP/dt but a significantly higher left ventricular end-diastolic(More)